Azo dye and method for its preparation



aqueous caustic soda and 30.0 parts of anhy- Patented Sept. 17, 1935 PATENT OFFICE AZO DYE AND METHOD For: rrs PREPARATION Clifford Paine, Handforth, England, Tassignor to Imperial .Chemical Industries Limited, a ,corporation of Great Britain N0 Drawing. Application 11115722, 1933, Serial No, 681,803. In Great Britain August 1=6 1932 Claims.

This invention relates to new aZo dyes and more particularly refers to new disazo dyes having the following general formula:

in which A represents the residue of diazo'tized' dehydrothiotoluidineor primuline-sulfonic acid, R represents an arylene nucleus, X represents a methyl or carboxylic acid group, and 'E' represents the residue of an aminonaphthol-sulfonic acid-or an 'N-substitution product thereof.

It is an object of this invention to produce new dyes having attractive shades. A- further object is to produce dyes having satisfactory fastness properties. A still further object is to produce disazo dyes which are particularly efiicacious -in coloring cotton and regenerated cellulose, these,

shades being generally brown :to orange-brown.

These objects .are attained according to the herein described invention, which in its preferred embodiment comprises couplin a .diazot zo de h droth u dineor mul eulion o d with a 1-aminoaryl-3-methyl-(or carboxyl) .5- pyrazolone, diazotizing the resulting aminoazo compound and coupling it with anaminon'aphthol-sulfonic acid or an N-substitution product thereof. Coupling of this latterfcompound may take place in acid, neutral or' alkaline solution.

"The invention may be more readily understood by a consideration of the following illustrative examples, in which the quantities are stated in parts by weight:

Example 1 32.0 parts of dehydrothiotoluidine sulfonic acid were dissolved in 15.0 parts of 30% aqueousicause tic soda-and600 parts of water. 35 partsof aqueous sodium nitrite were then added and followed, at a temperature of 1520 C. by 35 parts of hydrochloric acid (sp. gr. 1.16). "Diazotiaation was allowed to proceed for one hour. The suspension of the diazo compound was thencoupled by gradual addition to an ice-cold solution of 18.0 parts of 1(m-aminopheny1) -3-methyl-5-py-' razolone in 300 parts of water, 15.0 parts of drous sodium carbonate. Formation of-the mono.- azo compound was rapid and after one hour the reaction mixture was heated to 80 C. and the coupling product isolated by the addition of 100 parts of common salt,fol1owed by filtration. The

monoazo compound 'was redissolved in 1000 parts of water and 25.0 parts of 30% aqueous caustic soda at a temperature of 70 -C., parts of 30% aqueous sodium nitrite were added and the mixture cooled to 25 0., when parts of hydrochloric acid (sp. gr. 1.16) were added rapidly. Diazotization :was substantially complete in 2 hours. The suspension ,of the diazo compound was then added gradually to an ice-cold solution of L30 par-ts of 2 phenylamino-5-naphthol-7- 10 in-ionic ac 500 part of w t r nd 53 parts o sodium ca bo ene was almost immediate and the disazo dyestuff so formed was finally isolated by the addition of 200 parts ,ofcommon salt, followed by filtration. The 15 new dyestufi dyed .cotton in orange-brown shades.

Example 2 'By substituting the 30 parts of phenylamino-5- naphthol-W-sulfdnic acid of Example 1 by 23.0 20 parts of -l-amino-8-naphthol-4sulfonic acid, a new dyestuff was obtained which dyed cotton in reddish brown shades.

Ex m e 3 ,-0' pa ts o th .monoa comp und obt ed by coupling dia q d y r0t w es fonic ,acid with 1(aminophenyl) -3-methyl-5- pyrazolone in the manner described in Example 1, were dissolyed in 1000 parts of water and 25.0 parts ,Qf 30% aqueous caustic soda at a temperaur lo 7 3. parts o 20% qu ou sodium nitrite were added and the mixture cooled to 20 C. when-38 parts of hydrochloric acid (sp. gr. 1.16) were rapidly added; After stirring for '2 hours the suspension of the diazoazo compound was first rendered-neutral to (Bongo red paper by the addition of sodium acetate crystals and then finally a solution of 260 parts of the sodium salt of -2- amino-i8-naphthole6-sulfonic acid in 500 parts of water was added. The mixture was allowed to stir for T8 hours when combination was substantially complete. The reaction mixture was then madeallgaline to litmus byl headdition of 20 parts of anhydrous carbonat and the .disazo dro tuf i olat d at tem e a u e o 79 c-byih addition of common salt. jlthe new dyestufi dyed cotton in orange shades.

Example 4 acid (sp. gr. 1.16). Diazotization proceeded for one hour. A solution of 25.5 parts of the hydrochloride of 1(p-aminophenyl)-3-carboxy-5-pyrazolone in 400 parts of water was then added to the suspension of diazo compound and sodium acetate crystals gradually added to the mixture until it was neutral to Congo red paper. Combination was complete within 3 hours and the monoazo compound was then isolated by the addition of salt and filtered. The monoazo compound was then redissolved in 1000 parts of Water and 25 parts of 30% aqueous caustic soda at 70 C. 35 parts of 20% aqueous sodium nitrite were added .and the mixture cooled to 25 C. when 45 parts of hydrochloric acid (sp. gr. 1.16) were rapidly added. After diazotizing for 2 hours the suspension of the diazoazo compound was added gradually to an ice-cold solution of 23.9 parts of 2-amino-5-naphtho1-7-sulfonic acid in 500 parts of water and 53 parts of anhydrous sodium carbonate. Coupling was rapid and the disazo dyestufi was isolated by the addition of common salt, followed by filtration. The new dyestuff dyed cotton and viscose in red-brown shades.

It is to be understood that the illustrative examples previously given are not intended as a limitation on the present invention. As already mentioned, the first component is a dehydrothiotoluidine-sulfonic acid or a primuline-sulfonic acid. Since the members of this class are well known it is not considered necessary to further discuss the compounds which'may be selected for this purpose.

The second component is 1-aminoaryl-3- methyl-(or carboxyl)-5-pyrazolone. While the l-aminophenyl derivative is preferable, it is to be understood that the invention is not restricted thereto since the l-aminonaphthol as well as other aminoaryl derivatives may be used with good results. It is preferable to have a methyl or carboXylic acid group substituted in the 3-position of this component. However other alkyl groups may be substituted for the aforementioned methyl group; likewise, other well known groups may be substituted for the carboxylic acid group. Furthermore, the amino group may be substituted in various positions in the aryl nucleus, and the positions given in this connection in the above examples are not to be construed as controlling.

The third component is an aminonaphthol-sulfonic acid or an N-substituted derivative thereof. As is obvious, numerous compounds come within this class and may be selected with satisfactory results. The amino, hydroxy and sulfonic acid groups may occupy various positions on the naphthalene nucleus. N-substitution products of this compound may be used with excellent results. The phenylamino substitution product thereof was given in Example 1 as an illustration of such derivatives. Since the characteristics and properties of a large number of these N-substitution products are well known it is to be understood that this invention is not confined to the aforementioned compound which was given solely for purposes of illustration.

The new compounds comprised herein are well adapted for dyeing cotton and regenerated cellulose. They produce thereon attractive colors, particularly brown, red-brown and orange-brown shades. These colors have satisfactory properties, and are a valuable addition to the azo dyes now in use.

As many apparently widely difierent embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims. I

I claim:

1. A process for producing azo dyes which comprises coupling a diazotized member selected from the group consisting of dehydrothiotoluidineand primuline-sulfonic acids with a member selected from the group consisting of l-aminoaryl- 3-methyl-5-pyrazolone and l-aminoaryl-3-carboxyl-5-pyrazolone, diazotizing the resulting aminoazo compound and coupling it with a member selected from the group consisting of aminonaphthol-sulfcnic acids and N-substitution products thereof.

2. A process for producing azo dyes which comprises coupling diazotized dehydrothiotoluidinesulfonic acid with l-aminophenyl-3-methyl-5-pyrazolone, diazotizing the resulting aminoazo compound and coupling it with an aminonaphtholsulfonic acid.

3. A process for producing azo dyes which comprises coupling diazotized primuline-sulfonic acid with a member selected from the group consisting of 1-aminoaryl-3-methyl-5-pyrazolone and 1-aminoaryl-3-carboxyl-5-pyrazolone, diazotizing the resulting aminoazo compound and coupling it with an aminonaphthol-sulfonic acid.

4. A process for producing azo dyes which comprises coupling diazotized dehydrothiotoluidinesulfonic acid with l-meta-aminophenyl-3-methyl-5-pyrazolone, diazotizing the resulting aminoazo compound and coupling it with a member selected from the group consisting of aminonaphthol-sulfonic acids and N-substitution products thereof.

5. A process for producing azo dyes which comprises coupling diazotized primuline-sulfonic acid with l-para-aminophenyl-3-carboxy-5-pyrazolone, diazotizing the resulting aminoazo compound and coupling it with 2-amino-5-naphthol- '7-sulfonic acid.

6. A20 dyes having the following general formula:

thol-sulfonic acid or an N-substitution product thereof.

7. Azo dyes having the following general formula:

9. A20 dyes having the following general formula:

8. A20 dyes having the following general forin which X represents a sulfonic acid group in mula: one case and hydrogen in the other case and Y in which R represents the residue of l-aminoaryl- 3-methyl-5-pyrazolone or 1-aminoaryl-3-carboxyl-fi-pyrazolone and E represents the residue of an aminonaphthol-sulfonic acid.

in which E represents the residue of an aminonaphthol-sulfonic acid.

c0 N=N-CH i 2 im represents an amino group or a phenylamino group.

10. An azo dye having the following formula: 25

CLIFFORD PAINE. 

